Trolley system.



C. J. HIXSON. TROLLEY SYSTEM. APPLICATION FILED AUG.6. 1914.

1,209,581. Patented Dec. 19,1916.

Inventor: Clihton J. Hixson,

His .DTttorney.

CLINTON J'. HIXSON, 0F SCHENECTADY, NEW YORK, ASSIGBIOR GENERAL ELECTRICCOMPANY, A CORPORATION 0F NEW YORK.

TROLLEY SYSTEM.-

Specification of Letters Patent. Patented Dec, 19, 1916.

Application filed August 6, 1914. Serial fio. 855,502.

vals with the object of minimizing their sag.

or the tension stress in them. as in the cate-. nary type ofconstruction.

Among. the advantagesobtainable in con nection with my-invention arehigh conductivity of the system; continuous contact of currentcollecting devices with conductors; large contact area and highconductivity or current capacity at the contact; uniform contactpressure; smooth running of collectors on conductors with the absence ofshock and arcing; and simplicity, ruggedness, and a cheapness ofconstruction. These and other advantages especially adapt my inventiontorailways where the traffic is dense and the trains are long, so thatvery heavy currents must be carried in the trolley system and must becollected at high speeds with the greatest practicable uniformity.

The principles and natures of my invention will appear from thefollowing discussion and from the subsequent description of lection ofcurrent as UIllfOI'lTl as possible by suspending these conductorsfronithe mess senger'means in recurrent succession, so to speak, insteadof in coincidence. I have found that a common messengercan be employedfor supporting the conductors, and

that in general such an arrangement is preferredj to separate messengersfor the indi vidual conductors,-both for the sake of simplicity ogionstrilction and because it particular embodiments, while its scope isdifficult to make the tension in separate messengers near enough aliketo secure an equality of the pressures between the collector and theseveral conductors as is necessary for the best results. 1 Theemployment of a common messenger has also the advantage of reducing thevariation in contact pressure as the collector traverses the conductors.

In order that each conductor may be entirely free to adjust itselflengthwise irrespective of another, itis best to suspend themindependently side by side from the common messenger; and as they areelectrically in parallel and at the same potential. I ordinarily preferto leave them en-' tirely unattached toone another and free to come incontact. at their-adjacent sides under the influence of gravity and theforces due to their currents and their charged condit-io n rather thanto go tothe trouble and expense of providing means to keep them apartwithout interference with tlieinlongitudinal adjustment. Indeedii'thiscontact of the conductors throughout their length is if anything anadvantage in making the conductivity a maximum on bothsides of thetrolley collector or contact device in case the latter losescont-actwith one of the conductors when passingone of its points ofsuspension. y

I haveherein illustrated and described in detail a catenary trolleysystem in which two conductors or trolley wires are suspended inalternation the particular embodiment of my invention shown being thebest at present known to me. W'hile,however, the inventionextends tovarious special combinations and arrange .ments of parts and specificfeatures and'details shown and describedyit is not confined thereto, orlimited to the use of no more than two conductors. but canbe variouslycarried of a pull-off device resembling. those shown in Fig. 4.

As shown in Fig.1, the flexible messenger 1 (such as a wire or a wirecable) is secured to. insulators on the arms 2 carried by the poles orposts 3. The two trolley wires 1 and 5 are freely and independentlysus-v pended'side by side from the messenger 1 by means of the hangers 6and-,7, the hanger clamps-8' and 9 which form the points of suspensionalternating at uniform distances along the wires, so those of one wireare midway between those of the other and the hard? spots of the onetherefore coincide with the softest spots of the other. The trolleywires 4 and 5 arevshown as slightly separated in Fig. 1, for the sake-ofclearnes's' of illustration; but it will be understood that in practicethey will be in contact with one another, .as shown in Fig. '2. Thetrolley wires 4 and 5 may preferably be of figure 8 or other groovedcross-section that 'will give good hold for the clanipsS and 9 and atthe same time-afiord such space for'the gripping portions of theseclamps. that they will not interfere unduly with the wires coming incontact. As will be 'seen from Figs. 2 and 3, the hangers 6 and 7consist of metal straps bent or loep'ed over the messenger 1 but notattached to it, andtheclamp jaw" pieces are riveted or otherwise securedto their lower ends and are held together by -the bolts 1O.-

It will be understood, of course, that the number, spacing, and lengthof the hangers 6 and 7 shown are merely illustrative, and

may in practice be varied according to the conditions of anyparticularcase'. Ordinarily a standard span of 150 feet betweenmessenger supports, aspacing of 15 feet between the hangers of .eachtrolley wire, and a hanger length varying in the span from 8 inches to26 inches will be found good practice. It is simpler and more coni'enient that f each trolley wire should have tlizsame'numberof hangersin each messenger span, but

a "this is'by no means essential. '45

" bf-construction for a curve,'the, curvature shown being of courseexaggerated as compared withordinary practice. Here there In Fig. 4 Ihave indicated a suitable mode is a 'wire 11 extending from pole topole, and

the-messenger 1 and the trolley wires t and 5are pulled off from thiswire 11 to keep 1 the messenger and two for each ofthe'trolleymemberto'one end of. which the them in suitable positions over the track,

there being four pull-ofi' points to a.- spanfor wires- It will be seenthat each pull-off point on a trolley wire is close-to one onthemessenger, so that a common pull-ofi' device 12 may be used for thep'ull-ofl' connection to thewire 11.(see'Figs. 4 and 5). There'a'revtherefore four pull-off 'devices to the span iiand as-showii theyare arranged in two gof two. Each pull-01f device 12 comsesand for thetrolley wire a. clamp" 14, a

a securing clamp 13 for the messenger clamp rigidly secured, and an arni16 rigidly secured to the other end of said member 15. To the clamp 13and the arm 16'are connected the ends of a wire 17 which securedto theends of a member 18 of channel The portion of the wire 17 between theclamp hooks 19 forms a sling whose middle is connected to the wire 11,an' insulator 20 being interposed in the connection. Different types ofinsulators are shown n Figs. '1

and 5, but otherwise the pull-off devices in these figures are alike.

It will be observed that the corresponding pull-oif ,points on the twotrolley wires do not coincide with one another or with any of thehangers, but are in every case at opposite sides of an interveninghangerfor onev of the wires, the obJect of this being to mini- 7 mize hardspots in the trolley wires and avoid coincidence of those in one wirewith those in the other. The pull-ofi points on the messenger-aresimilarly arranged out of same horizontal plane, just-as in the tangentconstruction of Fig. 1; but owing to the noncoincidence of theircorresponding pull-off points they can not be in contact everywhere, anda s shown do not touch at all. It will be understood, of course, that inpractice there may be more hangers and pull-ofi' points in a curve-spanthan are shown in Fig.

- 4, that the pull-offs may be differently arranged,-and thatthe spanwill ordinarily be longer in proportion to the hanger spacing. For anordinary two or six degree curve the messenger spans may be 150 feet,the hanger spacing maybe 15 feet for each wire. and four pull-offdevices arranged as in Fig. 4:

may be employed. In this case the pull-off 7 devices of each group maybe 15 feet apart and the nearest ones of adjacent groups may be feetapart. A conductor supported at intervals such in comparison with itstransverse strength that it is properly to be regarded as flexible willhang between the points of support in a series of more or less fiatloops,no matter how great the tension on'it may he,and at the points ofsupport it will bebent upward f more or less abruptly. When acurrentcollector or contact device travels along a single trolley conductor sosupported, it will l ft theloops more or-less, and-may even 11ft theconductor somewhat (though less loop hangers 6 and 7. In spite of this lftmg of the trolley conductor, however,'when .70 section by means ofeyes-or clamp hooks .19. i

readily) at the points of support,.-if the. I mode'of support permitsit, as do the 0 en' the collector comes to the bend at a point ofsupport it will jump from one loop to the next and will lose contactwith the conductor for a short distance as it does so. Vhile thecollector is out of contact with the conductor an arc will occur and thecurrent col-- the higher the speed;. and the trouble will also be worseor more serious the greater the voltage and the heavier the current. Itwill alsobe worse for direct current than for alternating current, In mytype oftrolley system comprising two or more trolley conductors with noncoincident support, the trouble just referred to is absent; for when thecollector comes to the hard spot 'at a point of support in the wire at,for example, it will still be in contact with a loop or soft spot in thewire 5, and vice versa. The result is that there will be no arc,.noshock, and no hammer,'the collector resuming contact and full pressureon the wire '4 gradually and quietly,all of which means smooth, even,quiet running and is favorable to high running speeds. It will furtherbe seen that :here will be less variation in the area, pressure, andcurrent carrying capacity at the contact; and uniformity in theserespects favors the handling of high currents satisfactorily almost asmuch as does the increased normal contact areafora given collector dueto the use of two trolley wires instead of one. The best results forhigh currents will be secured by using a pantograph trolley with a bowcontactor or collector having a liberal width of contact surface ratherthan one with a roller collector.

The multiple conductor catenary construction has important advantagesover a direct suspension construction employing a plurality ofconductors. In the first place, single conductor ca-tenaryconstructionpermits a messenger span and support spacing of, say, 150feet to 300 feet, ascompared with a maximum of about 100 feet for singleconductor direct suspension construction, and aflords various otherwell-known advantages. In the second place, multiple conductor, catenaryconstruction permits the same messenger span and support spacing assingle conductor-catenary construction,

whereas multiple conductor direct suspension constructionpermits only9;, or 5'; the support spacing, according to the number of conductors.For two conductors, thereplurality of horizontally -tors for supplyingcurrent to the same confore, the catenary construction requires only to{,7 the number of poles required by the other. Again, the catenaryconstruction results in the collector being always in contact with oneor the other of the conductors and nearly always in contact with both ofthem, and also in a much greater uniformity of contact pressure; and theresult of all this is that the average contact area and current capacityare much higher.

hat I claim as new and desire tosecure by Letters Patent of the UnitedStates, is

1. A catenary trolley system comprising a stretched conductact devicesuspended from means in alternation.

2. A catenary trolley system comprising a pair of horizontallystretchedconductors for supplying current to the same contact device suspendedside by side from a common messenger, the points of suspension of eachof said conductors alternating with those of the other.

3. A catenary trolley system comprising a plurality of horizontallystretched conductors for supplying current to the same contact devicesuspended side by side and free to come in contact at their adjacentsides but unattached to one another, the successive points of suspensionof the respective conductors from the messenger means being themselvesarranged in recurrent succession.

4. A catenary trolleysystem comprising a pair of horizontally stretchedconductors for supplying current to the same contact deviceindependently suspended side by side from a common messenger and free tocome in contact but unattached to one another, the points of suspensionof each of said conductors being midway between those of the other.

5. The combination with a messenger cable and a pair of trolleyconductors, of means for freely suspending each of said conductors fromsaid messenger cable where by said conductors tend to lie in contactwith each other.

6. The combination with a messenger cable and a pair of trolleyconductors, of a plurality of staggered hangers of equal length foralternately pivotally suspending each of said conductors from saidmessenger cable whereby said conductors tend to lie in contact with eachother.

In witness whereof, I have hereunto set my hand this 5th day of August,1914.

- CLINTON J. HIXSON.

the messenger Witnesses MARGARET E. WOOLLEY, HELEN ORroRD.

